1. Field of the Invention
The present invention relates to safety valve for preventing the uncontrolled release of high pressure fluids in the event of catastrophic failure in the fluid conducting equipment downstream of the safety valve.
2. Description of the Prior Art
Many applications require the confinement of hazardous fluids in high pressure bottles. For example, in welding, oxygen and acetylene are confined in bottles under high pressure. In such applications, a breakage in a valve or gas line downstream of the bottle can lead to an uncontrollable release of high pressure gas. High pressure gas issuing from the attachments to the bottle can propel the bottle at high velocity causing injury to persons in the vicinity of the bottle. In addition, uncontrolled discharges of gases such as oxygen and acetylene can lead to an explosion hazard.
To overcome the hazards of uncontrolled gas discharge several safety valves have been proposed in the prior art. However, none of the prior art valves providing for automatic shut-off of the gas flow in the event of catastrophic failure downstream of the pressure source, have the simplicity of design of the present invention.
U.S. Pat. No. 4,089,343, issued to Ishida, shows a safety valve wherein a sealing member is moved to its sealing position in response to high pressure downstream of the valve. This condition can occur in response to a line blockage downstream of the valve. Clearly this valve design would be ineffective in stopping flow in case of loss of gas containment downstream of the valve.
U.S. Pat. No. 4,349,043, issued to Christensen, shows a safety valve wherein a sealing member is moved to its sealing position in response to high pressure upstream of the valve. In the Christensen design, catastrophic breakage downstream of the valve would cause even greater opening of the valve. Thus the Christensen device acts in a way totally opposite to the action of the present invention.
U.S. Pat. No. 4,611,628, issued to Pasternack, shows a pressure attenuator that retards the impact of a pressure wave when a manual shut-off valve to a high pressure bottle is first opened. The Pasternack device is incapable of completely shutting off escape of gas from the bottle in the event of a breakage in the line downstream of the device.
U.S. Pat. No. 4,744,387, issued to Otteman, shows a pressure regulator valve wherein a sealing member is moved to its sealing position in response to high pressure upstream of the valve. In the Otteman design, catastrophic breakage downstream of the valve would cause even greater opening of the valve. Thus the Otteman device acts in a way totally opposite to the action of the present invention.
U.S. Pat. No. 5,022,435, issued to Jaw-Shiunn, shows combination pressure regulator and safety shut-off valve. Jaw-Shiunn show a spring loaded ball or the in-line configuration of the present invention. Further, the Jaw-Shiunn device requires a plunger to reset the ball unlike the present invention.
U.S. Pat. No. 5,123,442, issued to Geuy et al., shows a safety shut-off valve having a floating valve seat which moves into engagement with a piston, in response to higher than normal pressure in the gas bottle, thus shutting off gas flow. The Geuy et al. device does not have the spring loaded ball or the in-line configuration of the present invention.
French Patent Document Number 1.087.683, by Ateliers la Locomecanique, shows a safety valve where a high pressure downstream of the valve causes the gas flow to be shut off. In the device of French Document '683, catastrophic breakage downstream of the valve would cause even greater opening of the valve. Thus the device of French Document '683 acts in a way totally opposite to the action of the present invention.
United Kingdom Patent Document Number 1 446 854, by King, shows a safety shut-off valve which shuts off gas flow when a gas line is disconnected manually from an appliance. The King device will not shut off gas flow in the event of breakage in the line or in the appliance, unlike the present invention which responds to any type of catastrophic failure.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.